1. Field of the Invention
The present invention relates to a conveyor apparatus for dies and the like small components used in, for instance, a die bonding apparatus, tape bonding apparatus, die packing apparatus.
2. Prior Art
In die bonding apparatuses, tape bonding apparatuses and die packing apparatuses, dies are conveyed in the following manner. As seen from FIG. 2, a wafer ring (not shown) is fastened to the outer circumference of a wafer sheet 2 to which dies 1 are bonded, and this wafer ring is moved in the directions of the X and Y axes by an XY table (not shown). The X-axis direction is the conveying direction of lead frames or substrates (hereafter collectively referred to as xe2x80x9clead framesxe2x80x9d) 5 that will be described later, and the Y-axis direction is the direction that is perpendicular to the conveying direction of the lead frames 5. A suction holding body 3 is installed beneath the wafer sheet 2, and a push-up needle 4 is installed inside the suction holding body 3 so that the push-up needle 4 is moved upward and downward. The lead frames 5 to which dies 1 are bonded are conveyed in the X-axis direction by a frame feeder 6.
A conventional die conveying apparatus is constructed in the following manner: an X-axis moving block 51 is installed on a base 50 so that this X-axis moving block 51 slides in the X-axis direction. The X-axis moving block 51 is driven via an X-axis feed screw (not shown) by an X-axis motor 52 that is mounted on the base 50. The upper and lower end portions of a Z-axis feed screw 53, which is installed in a vertical orientation (i.e., in the direction of the Z-axis) on the X-axis moving block 51, are supported so as to be rotated. The Z-axis feed screw 53 is driven by a Z-axis motor 54 that is mounted on the X-axis moving block 51. The upper and lower end portions of a Z-axis guide rod 55, which is disposed parallel to the Z-axis feed screw 53, are fastened to the X-axis moving block 51; and a Z-axis moving block 56, which is disposed in the Y-axis direction, is installed on the Z-axis guide rod 55 so that the Z-axis moving block 56 can slide. A Z-axis feed nut (not shown) is fastened to the Z-axis moving block 56 and screw-engaged with the Z-axis feed screw 53.
The left and right end portions of a Y-axis feed screw 60 that is oriented in the Y-axis direction are supported on the Z-axis moving block 56 so that the Y-axis feed screw 60 is rotated. The Y-axis feed screw 60 is driven by a Y-axis motor 61 mounted on the Z-axis moving block 56. The left and right end portions of a Y-axis guide rod 62, which is disposed parallel to the Y-axis feed screw 60, are fastened to the Z-axis moving block 56; and a Y-axis moving block 63, which is disposed in the direction of the Z-axis, is installed on the Y-axis guide rod 62 so that the Y-axis moving block 63 can slide. A Y-axis feed nut 64 is fastened to the Y-axis moving block 63 and screw-engaged with the Y-axis feed screw 60.
A nozzle holder 70 is installed on the Y-axis moving block 63 so that the nozzle holder 70 can slide in the vertical direction (i.e., in the direction of the Z-axis), and a suction chucking nozzle 71 is fastened to this nozzle holder 70. The suction chucking nozzle 71 is urged downward by a spring (not shown) so as to contact a stopper 72 that is fastened to the Y-axis moving block 63. The suction chucking nozzle 71 vacuum-suctions the dies 1 with a vacuum means (not shown).
The operation of the above prior art apparatus will be described.
As shown in FIG. 2A, when the suction chucking nozzle 71 approaches the die 1 that is to be picked up in the die pick-up position 7, the push-up needle 4 is raised. As a result, the die 1 is caused to contact the suction chucking nozzle 71, and the suction chucking nozzle 71 holds the die 1 by vacuum suction. Next, the Z-axis motor 54 and Y-axis motor 61 are rotated in the reverse direction. When the Z-axis motor 54 is rotated in the reverse direction, the Z-axis feed screw 53 is rotated to raise the Z-axis moving block 56, and the nozzle holder 70 and suction chucking nozzle 71 are moved upward together with the Y-axis moving block 63. When the Y-axis motor 61 is rotated in the reverse direction, the Y-axis feed screw 60 is rotated and raises the nozzle holder 70 and suction chucking nozzle 71 together with the Y-axis moving block 63 in the Y-axis direction toward the lead frame 5. As a result, the suction chucking nozzle 71 is moved to a point above the die bonding position 8 as shown in FIG. 2B. Afterward, the Z-axis motor 54 is rotated in the forward direction so that the nozzle holder 70 and suction chucking nozzle 71 are lowered together with the Y-axis moving block 63, and the die 1 is bonded to the lead frame 5. After this die bonding, a reverse operation of the above-described steps is performed so that the nozzle holder 70 and suction chucking nozzle 71 are moved to the die pick-up position 7.
In die bonding apparatuses, in order to reduce the amount of spaces, the wafer sheet 2 and lead frame 5 are not disposed in a plane arrangement. Instead, these elements are disposed so that part of the wafer sheet 2 is positioned beneath the frame feeder 6. As a result, it is necessary to move the suction chucking nozzle 71 vertically (in the direction of the Z-axis) for the distance that is defined by adding a spare amount of height to the vertical height of the wafer sheet 2 and lead frame 5.
In the prior art, heavy objects such as the Z-axis moving block 56, Y-axis motor 61, Y-axis guide rod 62, Y-axis feed screw 60, Y-axis moving block 63 and nozzle holder 70 are driven up and down by the Z-axis motor 54. Accordingly, the Z-axis motor needs to have a great amount of driving output. Further, in the prior art, it is impossible to perform high-speed vertical driving.
Accordingly, an object of the present invention is to provide a conveyor apparatus for conveying dies and small components in which the weight of the constituting elements that are driven upward and downward is greatly reduced.
It is another object to provide a conveying apparatus that does not need a motor for vertically driving the suction chucking nozzle, so that the cost of the apparatus can be greatly reduced, and so that the suction chucking nozzle is driven upward and downward at a high speed.
The above objects are accomplished by a unique structure for a conveying apparatus that comprises:
an X-axis moving block which is moved in the X-axis direction that constitutes a conveying direction of a lead frame, etc.,
a Y-axis moving block which is installed on the X-axis moving block and moved in the Y-axis direction that is perpendicular to the X-axis direction,
a nozzle holder which is installed on the Y-axis moving block so that the nozzle holder is movable upward and downward,
a Z-axis guide rail which is installed on the X-axis moving block and has an inclined part that rises from the die pick-up position side toward the die bonding position side,
a Z-axis moving plate which is moved upward and downward along the Z-axis guide rail and is connected to the nozzle holder, and
a suction chucking nozzle that holds dies by vacuum suction and is installed so as to be movable upward and downward on the nozzle holder and moved upward and downward together with the nozzle holder.